tbuckley/cabot-search huggingface dataset:
Abstract P3024: Mitochondrial Dysfunction Underlies Sinoatrial Node Dysfunction In Heart Failure With Preserved Ejection Fraction
Authors: Thassio Mesquita, Rodrigo Miguel-dos-Santos, Aleksandr Stotland, Xaviar Jones, Jacob Motawakel, Jae H Cho, Mario Fournier, Weixin Liu, Eduardo Marban, Eugenio Cingolani
Journal: Circulation Research (2022)

Background: Metabolic comorbidities are frequent in patients with heart failure with preserved ejection fraction (HFpEF). We recently demonstrated that chronotropic incompetence and exercise intolerance are associated with intrinsic sinoatrial (SAN) dysfunction in animal models of HFpEF. However, there are no studies investigating whether metabolic dysfunction in HFpEF can lead to mitochondrial dysfunction in the SAN. Hypothesis: Our recent findings uncovering SAN pacemaker dysfunction in HFpEF upon metabolic stress led us to test the hypothesis that mitochondrial dysfunction may underlie this condition. Methods: Male C57Bl6 mice fed high fat diet (HFD) plus nitric oxide inhibitor (L-NAME) or regular chow served as HFpEF and control, respectively. Optical mapping, transcriptomics, targeted quantitative proteomics of mitochondrial proteins, mitochondrial respiration and reactive oxygen species (ROS) assays were conducted using explanted mouse SAN tissue or isolated pacemaker cells. Results: SAN from HFpEF-verified animals after 20 weeks of HFD+LNAME exhibited prolonged SAN recovery time after pacing (100%; P&lt;0.05). RNA sequencing revealed augmentation of gene clusters related to metabolism (i.e. ucp and pdk4 ) and extracellular matrix expansion (i.e. col, postn and Cilp1 ). Targeted proteomics validated SAN RNA-sequencing findings, showing upregulation of proteins related to ROS scavenging, fatty acid transport and TCA/OXPHOS (i.e. SOD, CPT2 and DHSA/B). Depressed maximal mitochondrial respiration was seen in isolated mitochondria from SAN of HFpEF animals compared to controls (-42%; P&lt;0.05). This was supported by increased generation of mitochondrial ROS in single pacemaker cells from HFpEF SAN (70%; P&lt;0.05). Acute mitochondrial dysfunction induced by a mitochondrial uncoupler (FCCP) elicited a pronounced prolongation of SAN recovery time in HFpEF compared to controls (165%; P&lt;0.05). Conclusion: Our results indicate that mitochondrial function is depressed in SAN from HFpEF animals, and is associated with SAN pacemaker dysfunction. Further studies are required to test cause-and-effect and to evaluate potential therapeutic strategies targeting mitochondrial pathways for HFpEF associated abnormalities of sinus rhythm.
Abstract P2070: Insights Into RBM20 Cardiomyopathy Revealed By Global Proteomics
Authors: Zachery R Gregorich, Eli J Larson, Yanghai Zhang, Ying Ge, Wei Guo
Journal: Circulation Research (2022)

Patients with missense mutations in RNA binding motif protein 20 (RBM20), an RNA binding protein and splicing factor, develop a clinically aggressive form of dilated cardiomyopathy (DCM). Recent studies revealed that DCM-linked RBM20 missense mutations promote re-localization of the protein from the nucleus to the cytoplasm where it forms ribonucleoprotein (RNP) granules—non-membrane bound assemblies formed from RNAs and RNA regulatory proteins. The sequestration of RNAs and RNA regulatory proteins in these granules has the potential to dramatically alter the landscape of protein expression in the cardiomyocyte; yet, how RBM20 missense mutations impact global gene expression at the protein level has not been explored. Herein, we utilized mass spectrometry (MS)-based proteomics to identify global changes in protein expression in cardiac tissue harvested from mutation knock-in (KI) mice harboring the DCM-linked S637A and S639G RBM20 mutations. Our analysis revealed a total of 212 and 190 differentially expressed proteins (DEPs) in S637A and S639G KI mice, respectively, relative to wild-type. In general, identified DEPs were similar between KI mice with 81 and 38 proteins commonly up- and down-regulated, respectively. Consistent with mutant RBM20-mediated granule formation, 15 and 12 of the up-regulated proteins in S637A and S639G KI mice, respectively, have previously been implicated in granule assembly. Other up-regulated proteins in KI mice included chaperones and cytoskeletal proteins, as well as proteins involved in RNA metabolism and metabolite interconversion. Interestingly, proteins involved in the regulation of metabolite interconversion were also the most common protein class down-regulated in both KI mice, suggesting that broad changes in cellular metabolism may be a common feature associated with the RBM20 S637A and S639G missense mutations. Additionally, our proteomics analysis confirmed the differential expression of approximately 20-30% of previously identified differentially expressed genes based on RNAseq analyses from S637A and S639G KI mice. Our results provide the first glimpse of global changes in gene expression at the protein level associated with the RBM20 S637A and S639G missense mutations.
Biology of small cell lung cancer: an overview
Authors: P Weynants, Y Humblet, JL Canon, M Symann
Journal: European Respiratory Journal (1990)

Despite disappointing results in the treatment of small cell lung cancer (SCLC), major progress in our understanding of SCLC biology has occurred in the past decade. Advances in the technique for culturing SCLC tumours in vitro have greatly facilitated the study of the biological properties of this tumour. The major progress in our understanding of SCLC includes: 1) the availability of nonspecific biological tumour markers such as neuron-specific enolase (NSE), the BB isoenzyme of creatine phosphokinase (CPKBB), bombesin/gastrin releasing peptide (GRP) and chromogranin A; 2) the generation of monoclonal antibodies raised against the neural and epithelial features of SCLC tumours; 3) the identification of several autocrine growth factors such as bombesin/GRP, insulin-like growth factor (IGF), transferrin and physalaemin; 4) the close study of cytogenetic abnormalities leading to the discovery of a unique chromosomal deletion of the short arm of chromosome 3 (del 3p 14-21), and to changes in oncogenic expression, e.g. c-myc, L-myc and N-myc, accounting for known biological and treatment results. These data suggest that all lung cancers arise from a common stem cell of endodermal origin. The information derived from these biological studies represents the most promising avenue towards new treatment strategies in SCLC.
Abstract P1032: Patterned Vessels In HIPSC-derived Engineered Myocardium Enhance Perfusion And Heart Regeneration In A Rat Myocardial Infarction Model
Authors: Rajeev Kant, Kiera Dwyer, Collin Polucha, Kareen L Coulombe
Journal: Circulation Research (2022)

Globally, &gt;6 million patients with heart failure (HF) have reduced ejection fraction due to prior myocardial infarction (MI). In the U.S., 50,000 become refractory to treatment each year and novel therapies are urgently needed to treat systolic dysfunction, as treatments to restore cardiac muscle are not available. Human embryonic or induced pluripotent stem cell-derived cardiomyocytes (hESC/hiPSC-CMs) have emerged as a leading candidate therapy for replacing CMs lost to MI and are being evaluated in preclinical models and clinical trials. Current delivery of CMs by intramuscular injection or engineered cardiac tissue is the first step in developing a new therapy but fails to address concerns of persistent ischemia in the host and implanted CMs. We hypothesize a dual remuscularization-revascularization therapy will promote vessel development to advance regeneration. We produce hiPSC-CMs and form human engineered myocardium (hEM) in custom molds by mixing CMs with 5% human primary cardiac fibroblasts in collagen. Sacrificial gelatin-alginate fibers coated with endothelial cells are embedded in the hEM to pattern patent channels 400 μm in diameter upon chelation and wash out of alginate. HEM is cultured with perfusion prior to implant in a rat model of ischemia/reperfusion MI to evaluate host-graft inosculation, perfused vascular bed morphology, graft size, and heart function at 2 weeks. Ex vivo optical coherence tomography reveals capillary-scale vessels in implants. Host vasculature and origin-tracking of inosculated vessels are quantitatively evaluated using micro-CT based 3D vascular reconstruction. Immunohistochemistry shows robust engraftment of hiPSC-CMs and chimeric vascular ingrowth in implants. Gene expression analysis from explanted hEM by bulk RNAseq is revealing a great benefit of vascularization on CM development of excitation-contraction coupling machinery and sarcomeres. In conclusion, remuscularization with revascularization therapy, featuring innovative approaches to pattern vessels, is enhancing multiple metrics of regeneration after hEM implantation. This study is the first of its kind and provides a new direction for development of regenerative therapies needed for the failing hearts of post-MI patients.
Abstract P1127: Electrical Stimulation For The Maturation Of Induced Pluripotent Stem Cell-derived Cardiomyocytes
Authors: Suh Hee Cook, Jack Twiddy, Michael Daniele, Jessica Gluck
Journal: Circulation Research (2022)

Heart disease is the leading cause of death in the U.S. and worldwide. Cardiac tissue engineering offers promising diagnostic tools and treatments. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are an attractive cell source for these tissue engineering applications due to their patient-specificity and theoretical capacity to supply limitless cell quantities. However, these hiPSC-CMs are immature compared to healthy, adult cardiomyocytes, demonstrating immature morphology, metabolics, and electrophysiology. Previous research has shown electrical stimulation shows promise in maturation of hiPSC-CMs. We aim to create an in vitro platform for the electrophysiological maturation of hiPSC-CMs using applied electrical stimulation during the differentiation process. We designed and fabricated a bioreactor for the application of electrical stimulation to hiPSC-CMs in culture. The bioreactor was created by laser cutting two parallel slits into the lid of a 12-well tissue culture plate, through which conductive Toray paper was placed. The space remaining between the slits and the Toray paper was sealed with polydimethylsiloxane (PDMS). Alligator clips were used to connect a function generator to the Toray paper. When sterilized with 70% ethanol, this modified 12-well plate lid can be used to apply electrical stimulation to cells cultured in a 12-well plate, as shown in Figure 1. Future work includes the application of electrical stimulation on day 3 of a well-established Wnti-directed monolayer protocol for the differentiation of hiPSCs into hiPSC-CMs. We expect to observe a resultant improvement in iPSC-CM’s genetic and electrophysiological maturation.
A bronchial butterfly
Authors: B Yung, C Norton, BH Davies
Journal: European Respiratory Journal (1994)

We report on an asthmatic patient who accidentally inhaled the small metal backing ("butterfly") of a nose stud, which she wore daily. Despite administration of nebulized salbutamol, postural drainage, and the use of rigid and fibreoptic bronchoscopes, attempted removal of the butterfly remained unsuccessful. Spontaneous expulsion of the butterfly occurred two months following inhalation. We suggest that consideration should be given by nose stud jewelry manufacturers to a more secure fixing device.
Abstract P1003: Mechanical Loading Controls Cardiomyocyte Proliferation
Authors: Giulio Ciucci, Andrea Colliva, Simone Vodret, Elena Zago, Manuel Maglione, Giovanni Cimmino, Paolo Golino, Gianfranco sinagra, Francesco Loffredo, Serena Zacchigna
Journal: Circulation Research (2022)

Introduction: Mammal cardiomyocytes (CMs) lose their proliferative capacity early after birth and switch to an adult phenotype, characterized by organized sarcomeres. The mechanisms that control this switch remain largely elusive. Among the changes experienced by the heart at birth is a sudden increase in mechanical load. Hypothesis: This study tests the hypothesis that variations in mechanical loading may regulate both the proliferation and the maturation of cardiomyocytes. Methods: Engineered heart tissues (EHTs) were generated using neonatal rat heart cells, with a modified protocol allowing to alter mechanical load. Unloading is obtained by reducing the distance between the silicon posts that anchor the extremities of the EHT, while overloading is induced by changing Young’s module of posts using metal braces. Adult heart unloading in vivo was achieved by heterotopically transplanting a mouse heart into the neck of syngeneic recipient mice, which were injected with EdU twice per week. Both hearts, native and transplanted, were harvested at day 30. Results: In line with our hypothesis, mechanical unloading of developed EHTs significantly increased the percentage of EdU-, Ki67- and pH3-positive CMs at 72 hours. In contrast, increasing afterload induced CM maturation, characterized by increased cross-sectional area and force of contraction, associated with reduced proliferation. Consistently, heterotopically transplanted hearts showed a significant increase in the the number of proliferating CMs in both ventricles, which were almost absent in native hearts. Conclusions: Our data indicate that mechanical unloading induce CM proliferation in both rat EHTs and an in vivo in a mouse model of heterotopic heart transplantation. These results support our initial hypothesis and indicate that mechanical loading is a master regulator of cardiomyocytes proliferation and maturation. Ongoing experiments aim at identifying the molecular mechanisms that regulate this process.
Abstract P1007: Cardiac Fibroblast BAG3 Controls TGFBR2 Signaling And Contributes To Engineered Cardiac Tissue Function.
Authors: Bryan Z Wang, Lori J Luo, Xiaokan Zhang, Margaretha Morsink, Rajesh Soni, Roberta I Lock, Youngbin Kim, Trevor Nash, Joshua Gorham, Barry Fine, Jonathan G Seidman, Christine E Seidman, Gordana Vunjak-Novakovic
Journal: Circulation Research (2022)

Introduction: Mutations in BAG3 result in dilated cardiomyopathy with cardiac fibrosis. Currently, the role of BAG3 in non-myocyte cell types is not known. We tested the hypothesis that BAG3 controls cardiac fibroblast (CF) function and that the loss of fibroblast-specific BAG3 is deleterious, using cells and engineered cardiac tissues (ECT) derived from pluripotent stem cells (iPSC). Methods: Isogenic iPSCs containing homozygous knockout (KO) of BAG3 were differentiated into CFs. Mass spectrometry measured the effect of BAG3 loss on CF proteome. EdU staining and flow cytometry were used to assess CF proliferation. Transforming growth factor beta (TGF) signaling pathway activity was measured using a luciferase reporter and Western blotting. Affinity purification mass spectrometry (AP-MS) identified high-confidence interactors of BAG3 in CFs. To assess the role of fibroblast-specific BAG3 in cardiac function, conditional KO ECTs were generated using wild-type cardiomyocytes mixed with either wild-type CFs or KO CFs. ECTs were functionally assessed using video microscopy and immunofluorescence. The effects of CF BAG3 loss on tissue gene expression are under study by single nuclear RNA sequencing. Results: Analysis of proteomics data revealed enrichment of TGF and proliferation pathways in KO cells. KO-CFs had increased proliferation measured by EdU staining and increased SMAD luciferase reporter activity. Western blotting showed that KO CFs have higher expression of TGF beta receptor 2 (TGFBR2) and activation of canonical TGF signaling. AP-MS identified TGFBR2 as an interacting partner of BAG3, suggesting BAG3 mediated TGFBR2 turnover. In ECT, the loss of CF BAG3 caused a reduction in cardiac tissue contractile force (50% reduction, n = 10-12 tissues per group). Immunofluorescence revealed significantly increased tissue fibrosis in CF-KO cardiac tissues quantified by vimentin staining. Conclusions: BAG3 loss results in increased TGFBR2 signaling and proliferation in cardiac fibroblasts. Conditional KO ECTs demonstrate that CF BAG3 affects tissue function. These data suggest that fibrosis related to BAG3 pathology may be a result of a primary deficiency in CFs rather than a secondary response to cardiomyocyte death.
Airway inflammation in symptomatic and asymptomatic children with methacholine hyperresponsiveness
Authors: I Pin, S Radford, R Kolendowicz, B Jennings, JA Denburg, FE Hargreave, J Dolovich
Journal: European Respiratory Journal (1993)

A definition of asthma includes symptoms due to reversible airflow limitation and airway hyperresponsiveness. Characteristically, there is also airway inflammation. In children with methacholine airway hyperresponsiveness but no asthma symptoms, we examined whether there were features of asthmatic airway inflammation. Forty one children, aged 11-16 yrs, were studied. Thirteen asymptomatic children with methacholine airway hyperresponsiveness (provocative concentration producing a 20% fall in forced expiratory volume in one second (PC20) geometric mean of 3.35 (range 1.08-7.81) mg.ml-1) were compared with 13 currently symptomatic asthmatics with a similar PC20 of 1.91 (0.42-6.5) mg.ml-1 and 13 normal children with a normal PC20 of 52.4 (17.6 to &gt; 64) mg.ml-1. Breathlessness experienced during a methacholine test was recognized to have occurred previously in 7 out of 13 asymptomatic children and all symptomatic children. Asymptomatic children had significantly more airway responses to hyperventilation with cold dry air (4 out of 13) than normal children (0 out of 13) but less than symptomatic children (11 out of 15). Sputum induced with hypertonic saline contained lower eosinophil counts in the asymptomatic children (median (interquartile range) 0.20 (0.59)%) than in the symptomatic children (1.70 (9.45)%), and not different from the normal children (0.15 (0.61)%). Budesonide, 400 micrograms b.i.d. improved respiratory symptoms, forced expiratory volume in one second (FEV1) and methacholine PC20 in symptomatic children, but this effect did not reach statistical significance in asymptomatic children. We conclude that symptomatic children are more likely to have evidence of asthmatic inflammation than asymptomatic children and this probably explains the symptom difference.(ABSTRACT TRUNCATED AT 250 WORDS)
Virus-induced airway hyperresponsiveness in man
Authors: PJ Sterk
Journal: European Respiratory Journal (1993)

Airway hyperresponsiveness is the most prominent functional abnormality in asthma. Although its aetiology is still unclear, it is well-known that allergen exposure and virus infections can temporarily induce or aggravate airway hyperresponsiveness. Among these environmental factors, virus infections appear to be clinically most relevant, since recent epidemiological studies have shown that most asthma exacerbations in children are associated with positive nasopharyngeal viral identification. The pathogenesis of virus-induced airway hyperresponsiveness has been investigated by experimental virus infections in animals and in man. Intranasal inoculation and/or inhalation of live attenuated influenza virus, or certain strains of rhinovirus, have been shown to induce airway hyperresponsiveness to various bronchoconstrictor stimuli in man. This indicates that experimental virus-infection, like allergen challenge, is an appropriate investigational model of asthma. The mechanisms of virus-induced airway hyperresponsiveness are still unclear, but may, in part, be similar to those involved in the pathogenesis of asthma. Currently investigated hypothesis include: epithelial damage or dysfunction, immunological responses, inflammatory mediator release, cholinergic and/or noncholinergic reflexes, and impaired beta-adrenoceptor function. Careful experimental studies, using modern laboratory techniques, are needed to unravel the role of viruses in the development of airway hyperresponsiveness. The results of such studies can potentially lead to an improvement of future asthma management.
Abstract P3039: NAD Redox Imbalance Exacerbates Diabetic Cardiomyopathy, Regulates Nmrk2 Expression And Alters NAD Synthesis
Authors: Keaton Minor, Haiwei Gu, Chi Fung Lee, Christine Light
Journal: Circulation Research (2022)

Heart failure occurs at twice the rate in diabetic patients compared to normal subjects. NAD redox imbalance or depletion has emerged as a hallmark of diabetes and heart disease. We showed that NAD redox imbalance or depletion promotes heart failure progression, but its role in diabetic cardiomyopathy has not been established. We used two mouse models with altered NAD metabolism. 1. Cardiac-specific NDUFS4-KO (cKO) mice which have mitochondrial complex I deficiency, decreased NAD/NADH ratio, but normal baseline cardiac function and energetics. 2. Cardiac-specific overexpression of nicotinamide phosphoribosyltransferase (NAMPT) in mice which elevates cardiac NAD levels. Diabetic stress induced by streptozotocin (STZ) promoted systolic (fractional shortening) and diastolic (E’/A’, e/E’) dysfunction, which were exacerbated in cKO mice. Overexpression of NAMPT to reverse NAD redox imbalance ameliorated cardiac dysfunction in both diabetic control and diabetic cKO mice. We measured expression levels of 58 genes related to NAD metabolism in these diabetic hearts. Transcript levels of genes for NAD consumption (sirtuins, PARPs and hydrolases) and NAD synthesis pathways (including NMRK1) did not change, except Nicotinamide Riboside Kinase 2 (NMRK2). NMRK2 transcript was upregulated in diabetic cKO hearts, associated with a decline in NAD levels. Expression of NAMPT to elevate NAD levels downregulated NMRK2 expression in both treated and untreated mice. The data indicate that upregulation of NMRK2 transcript is negatively correlated with cardiac function and NAD levels. NMRK2 is an enzyme involved in the Preiss-Handler and Salvage pathways of NAD synthesis by phosphorylating the NAD precursor Nicotinamide Riboside (NR) into Nicotinamide Mononucleotide (NMN). NAD metabolite analysis in the heart tissue showed a trended increase in the substrate of NMRK2, NR, and a trended decrease in the products, NMN or NAMN in diabetic cKO hearts with a decline in NAD levels. Our results suggest that NAD redox imbalance drives the progression of diabetic cardiomyopathy, and NMRK2 upregulation may regulate disease progression and NAD synthesis through mechanisms to be determined.